A woodwind instrument, such as a clarinet, includes a mouthpiece section, a barrel section and a bell section. The pitch of the instrument can be lowered by moving the mouthpiece section away from the barrel section, thereby lengthening an air column within the instrument. The pitch of the instrument changes in response to ambient temperature and humidity, and to heat and moisture introduced by a player's breath. Although thermally induced changes in pitch can sometimes be compensated for by manually shifting the position that the mouthpiece is seated within the barrel, this maneuver is cumbersome, and therefore cannot be accomplished while playing the instrument. It is very inconvenient and disruptive to interrupt a musical piece to affect this adjustment. Furthermore, since thermally induced pitch changes are slight, but nevertheless perceptible, the adjustment of the mouthpiece with respect to the barrel must also be made precisely. This can be difficult, because the same properties that allow the mouthpiece to remain lodged within the barrel prevent smooth, precise adjustments.
A tuning barrel can facilitate this adjustment. The tuning barrel is included between the mouthpiece and the main body of the woodwind instrument. Tuning barrels and the like are well known in the art. However, known devices cannot be adjusted easily during play, and do not lend themselves to precise pitch adjustments. Furthermore, some tuning barrels do not allow the mouthpiece to be rotated with respect to the main barrel section, and some barrels themselves have poor thermal expansion properties and less than satisfactory vibratory responses. Moreover, early models are difficult to manufacture.
In particular, Bushnell U.S. Pat. No. 2,802,387 teaches a tuning device for musical instruments that includes a set screw for locking a tuning section in a selected position with respect to a barrel section, and for providing a desired telescopic adjustment. Bushnell lacks any threading between the tuning section and the barrel section, and therefore is not capable of the degree of precision adjustment that such threading facilitates. Additionally, adjustment of the set screw is difficult to accomplish during play.
Also, Reynolds U.S. Pat. No. 1,171,647 discloses a tuning slide for clarinets that includes an off-axis guide pin that serves to prevent turning of the mouthpiece of the clarinet with respect to its body upon adjusting the slide tube when tuning the clarinet. Furthermore, Reynolds depicts an adjusting ring of such thinness that the extent of overlap between the threads on a slide tube is consistently insufficient to provide lateral stability with respect to the central axis of symmetry unless the guide pin is also present to provide such stability. However, it is known in the art that it would be desirable if it were possible to both rotate the mouthpiece with respect to the body of a clarinet, or other woodwind instrument, and precisely adjust the length of a tuning barrel incorporated therein. Also, a thin adjusting ring is awkward to locate and uncomfortable to adjust. Furthermore, because most of the metal parts are not exposed, being covered in ebonite, the thermal dissipation properties of Reynolds's device are inadequate to provide satisfactory thermal properties.